Thermostat



Patented June 10, 1930 UNITED STATES PATENT OFFICE cLAnEncn n. moanow, or CLEVELAND, OHIO, ASSIGNOR 'ro Hors'rnnm HEATER compan or CLEVELAND, 0310, A coaroaa'rron or OHIO THERMOSTAT Application filed larch 30, 1929. Serial 170. 351,267.

This invention relates to thermostats such as are used for domestic hot water heating systems. The invention is more particularly applicable to that type of thermostat in which the thermostatic elements include the usual two members difiering in coeflicient of ex ansion, one of them including a member ad ustable as to one dimension, such as length, for varying the closing point of the valve, and said thermostatic members including in the chain or train thereof endwise abutting members not connected to each other, the object of the invention being to provide means for maintaining a light endwise pressure upon said members so as to frictionally hold the adjustable members by reason of said pressure in the position to which they may be adjusted and avoiding change of adjustment by shock and ar, such as frequently occurs 'in these devices.

Further objects of the invention are in part obvious and in part will appear more in detail hereinafter In the drawings, which represent one suitable embodiment of the invention, Fig. 1 is a central longitudinal sectional view; Fig. 2 is a cross section on the line 22, Fig. 1, with the diaphragm partly broken away to expose the pressure spring; and Fig. 3 is a detail section on the line 3-3, Fig. 1. I

The present invention is an improvement upon the thermostat shown and described in m 13 79465, to which reference may be had for a more complete description thereof if necessary. Briefly described, said thermostat comprises a hollow casing including a body member 1 threaded at 2 for screwing it into the boiler connection and at its opposite end carrying a' valve bodv member 3 provided with a cross wall 4 having a large valve opening closed by the movable valve member 5, the chambers on opposite sides of the cross wall being provided with gas supply and discharge connections 6, 7. The valve is yieldably moved toward its seat by a compression spring 8 held beneath the cap 9, while it is moved away from itsiseatby the contraction of the relatively expansible one of the two thermostatic members, such as pencil 13.

patent for Thermostatic valve, No.

the copper tube 10 brazed or otherwise rigidly connected at 11 to the body 2 and having its inner end closed at 12 by a cross wall forming an abutment, against which rests one end of the relatively non-expansiblo thermostatic element, such as the carbon The forward end of the carbon pencil rests against or abuts, but is not connected to, a member 14, which is in the form of an internally threaded sleeve screwed upon the threads of the" reduced extension 15 of a valve stem, the opposite end 16 of which enters and seats in a recess in the valve 5.

Member 14 has adjustably connected thereto a finger 17, the outer end of which travels along an edge of the casing and usually c0- operates with indicating marks thereon so as to provide an operator for adjusting the valve and providing an indication of its po.- sition of adjustment. This finger can be rotated upon and secured to the member 14 by the set screw18, and when secured thereto rotation of the finger turnsthe member 14 and adjusts it along the threads of the stem '15 and, in efiect, shortens or lengthens the valve stem so as to vary the seating of the valve and determine the temperature to which the gas supply is cut ofi.

Escape of gas from the inner chambers of the mechanism is of course prevented by the usual metal or other form of flexible diaphragm 19 secured against an annular shoulder 20 of the valve stem by the clamping nut 21 and having its peripheral edge clamped between members 1 and 3 of the casing.

In devices of this kind, assuming the valve open, the gas flows through the valve mechanism to the burner and the temperature of the water rises and expands the copper tube lengthwise, permitting the spring 8 to move the valve untilit reaches its seat, but there transmitted beyond the valve 5 after the valve seats. Member 14 is therefore more or less looseuponthe threaded extension 15 and shocks or jars, such as are caused by heavy trucks passing the house may cause the finger 17 to move around or drop as far as the valve construction will permit, even to a degree which very materially reduces or changes the temperature atwhich the valve seats.

Ihave therefore provided the valve mecha nism with means for maintaining some endwise pressure through the chain or train of thermostatic elements and operating mechanism to the valve for frictionally holding member 14: in the position to which it is ad justed. The means shown comprises a light leaf spring 22 in the form of a flat plate or strip provided with a central opening so that it can be slipped over the valve stem and clamped upon it between shoulder 20' and nut 21 adjacent to the diaphragm 19. The opposite outwardly extending ends of the spring are bent longitudinally of the valve stem and engage the fixed wall 23 of the easing body. These spring arms are so flexed that they are under tension during all positions and conditions of adjustment of the valve mechanism, constantly producing pressure endwise to the left in Fig. 1 and, in

deed, pressure which is sufficiently strong so that the leaf spring can flex the diaphragm 19, which is quite flexible. With this arrangement, when the valve 5 seats as before and the copper tube continues to expand, the leaf spring 22 moves the dia hragm 19 to the left and causes mem )er 14 to follow up the carbon pencil with a continuously exerted pressure between the threads of member 14 and the threaded stem 15, the friction between said threads holding the finger 17 in any position to which it may be turned. Such friction is sufficiently great to prevent the finger from jarring loose or being moved otherwise than by an intended adjustment.

What I claim is:

1. Thermostatic valve mechanism, comprising a valve casing containing an adjustable valve member, an operating train including thermostatic elements extending from the casing to the valve member and including an adjustable device for varying the valve setting, the train of thermostatic elements including endwise abutting members, and means for maintaining pressure upon said adjustable member to prevent accidental change of adjustment thereof.

2. Thermostatic valve mechanism, comprising a valve casing containing a valve member, a train of operating mechanism for the valve extending from the casing to the valve and including thermostatic elements, two members relatively adjustable longitudinally for varying the valve setting, and yielding means for applying pressure to said member, one wall of said casing being closed,

by a flexible diaphragm, a valve stem extending through said diaphragm, yielding means between the diaphragm and valve casing, thermostatic members connected to the valve body,'and relatively adjustable means between said diaphragm and one of the thermostatic elements.

In testimony whereof I hereby affix my signature.

CLARENCE H. MORROW. 

